JP4949097B2 - Powder paint recovery equipment for powder coating equipment - Google Patents

Description

  The present invention relates to an apparatus that separates a carrier air and a powder paint and collects the powder paint in a paint tank when the powder paint is conveyed to the paint tank by the carrier air.

  In the powder coating apparatus, new powder as overspray powder or replenishment powder is collected in a paint tank, and the collected powder paint is supplied from the paint tank to a coating gun by an injector.

  By the way, conveyance of overspray powder or replenishment powder to the paint tank is carried by air using conveyance air.

  For example, in the case of overspray powder, as shown in FIG. 4, the overspray powder in the painting booth 21 is collected using a dust collector 23 having a cartridge filter 22 and is installed near a painting gun 24. Then, the air is conveyed by the conveyance injector 26 via the conveyance hose 27.

  When a powder coating material such as overspray powder or replenishment powder is transported by transporting air, a cyclone 28 for separating the overspray powder from the transporting air is required above the paint tank 25.

  The cyclone 28 is made to flow into the funnel-shaped or cylindrical cyclone body together with the carrier air in a vortex, and the carrier air is naturally exhausted upward from the center of the circle of the cyclone body. This is a device for centrifuging paint to collide with the wall surface of the cyclone body and then dropping it under the cyclone body by gravity to collect the powder paint in the lower part of the cyclone body. The natural exhaust exhausted from the cyclone 28 is sent to the painting booth 21 via the duct 29.

  As described above, the cyclone 28 is a device that exhausts the carrier air upward from the center of the circle of the cyclone main body and separates the powder from the carrier air. It is necessary to air-lock by the rotary valve 30 shown in FIG. 5 or the pinch valve 31 shown in FIG.

  As shown in FIG. 5, the rotary valve 30 includes a rotor 36 having a plurality of blades 35 installed in a horizontal cylindrical casing 34 provided with a supply port 32 and a discharge port 33 at the top and bottom. Thus, the device discharges the powder while performing an air lock between the upper and lower supply ports 32 and the discharge port 33.

  On the other hand, as shown in FIGS. 6A and 6B, the pinch valve 31 houses a cylindrical rubber pipe 40 in a vertical cylindrical casing 39 provided with a supply port 37 and a discharge port 38 on the upper and lower sides. As shown in FIG. 6B, the compressed air is injected from the compressed air supply pipe 41 between the cylindrical casing 39 and the rubber pipe 40, thereby contracting the rubber pipe 40, and the supply port 37 and the discharge port. This is a device that closes the space 38 and maintains an air-locked state, thereby blocking outflow of powder. Then, when the supply of compressed air from the compressed air supply pipe 41 is stopped, the rubber pipe 40 is opened and the air lock state is released as shown in FIG. Powder can flow out.

  Next, in the case of overspray powder, since dust and the like are mixed, the powder coating material separated and recovered by the cyclone 28 is naturally dropped on a selection device installed below the cyclone 28, for example, a vibration sieve 42, The dust mixed with the powder paint collected by the sieve screen is carefully separated and collected, and then collected in the paint tank 25.

  Further, since the amount of powder paint in the paint tank 25 is reduced only with the collected overspray powder, the new powder 43 is replenished to the paint tank 25 as supply powder.

  Air conveyance may also be used for conveying the new powder 43 to the paint tank 25. In this case, a cyclone 28 for separating the powder paint and the conveyance air is provided above the paint tank 25. Necessary.

  By the way, in the apparatus that separates the carrier air and the powder paint and collects the powder paint, the lower part of the cyclone 28 is air-locked by the rotary valve 30 and the pinch valve 31.

  However, when the rotary valve 30 is used, when the powder paint accumulated in the lower part of the cyclone 28 is taken out, the powder paint is put in the gap between the cylindrical casing 34 of the rotary valve 30 and the blade 35 of the rotor 36. There is a problem that a lump of powder coating is easily formed by being sandwiched, and this lump causes generation of fluff.

  Further, when the pinch valve 31 is used, as shown in FIG. 6B, the rubber pipe 40 is forcibly pressed and closed by compressed air from the outside, so that the powder paint is strongly compressed in the rubber pipe 40. There is a problem that the powder coating lump is easily formed by the compression, and this lump also causes the generation of blisters.

Further, when the rotary valve 30 is used, the blade 35 of the rotor 36 is easily damaged, and the blade 35 needs to be frequently replaced. Further, when the pinch valve 31 is used, since the rubber pipe 40 is forcibly compressed by compressed air, there is a problem in that the life of the rubber pipe 40 is severely deteriorated and the life of the rubber pipe is easily cracked.
Moreover, since the rotary valve 30 and the pinch valve 31 are expensive, there is also a problem that the equipment cost increases accordingly.

  Therefore, the present invention provides a powder coating material that does not cause a strong compressive force to the powder coating material and can greatly reduce the equipment cost when the air lock is applied to the lower part of the cyclone that separates the powder coating material and the conveying air. A collection device is to be provided.

In order to solve the above-mentioned problems, the present invention provides a cyclone for separating the carrier air and the powder paint at the upper part of the paint tank, conveys the powder paint to the cyclone by the carrier air, In the powder coating device that discharges upward from the center of the cyclone circle, drops the powder paint down the cyclone and separates it from the carrier air, and stores the separated powder paint in the paint tank installed below the cyclone In the powder paint recovery device, a transport injector that supplies powder paint along with transport air to the cyclone is installed , a flexible tube is connected to the outlet below the cyclone, and a forced exhaust device is connected above the cyclone. and actuates the conveying injectors, the force at the time of supplying the powder coating by the conveying air to the cyclone The flexible device connected to the lower outlet of the cyclone is contracted and closed by this forced exhaust, and the forced exhaust device is stopped to open the flexible tube below the cyclone. It is.

In the present invention, when the powder coating material is supplied to the cyclone by the carrier air, the forced exhaust device is driven to perform the forced exhaust from above the cyclone. Due to the upward suction action by the forced exhaust, the flexible tube below the cyclone contracts inward, the lower part of the cyclone is closed in an air-locked state, and the powder coating is deposited above the closed flexible tube.
When the forced exhaust system is stopped, the upward suction action of the cyclone disappears, so the flexible tube spreads outward, the flexible tube opens, the air lock is released, and the powder coating deposited above the flexible tube is Fall into.

As described above, according to the present invention, the flexible tube below the cyclone is opened and closed by turning on and off the forced exhaust device, so it is necessary to air-lock the lower portion of the cyclone using an expensive rotary valve or pinch valve. Absent.
In the present invention, the flexible tube installed below the cyclone can be an inexpensive tube such as a candy rubber tube as long as it contracts due to the suction force from above the cyclone. Can be planned.

  In this invention, since the powder paint naturally falls from the flexible tube to the paint tank, it is possible to prevent the conveyance air from being brought into the paint tank, and the powder paint scatters from the inspection port when inspecting the paint tank. There is no, and does not pollute the work environment.

  In addition, since the pressure in the paint tank can be kept constant, the discharge amount sucked and conveyed from the paint tank to the gun by an injector or the like can be stabilized, and coating defects such as excessive film thickness can be prevented.

FIG. 1 shows an overspray powder recovery flow using the powder coating material recovery apparatus according to the present invention.
The overspray powder in the painting booth 1 is collected using a dust collector 3 having a cartridge filter 2.

  The overspray powder collected in the dust collector 3 is sent to the cyclone 8, the vibration sieve 10, and the paint tank 5 by the air conveyance via the conveyance hose 7 by the conveyance injector 6 installed below the dust collector 3. The overspray powder collected in the paint tank 5 is mixed with the new powder 12 and then sent to the coating gun 4 for reuse.

  When the powder coating is transported by transporting air, the powder coating and the transporting air are mixed. Therefore, a cyclone 8 is installed above the paint tank 5 in order to separate the powder coating from the transporting air. ing.

  In addition, the new powder 12 replenished to the paint tank 5 is also supplied by air to the paint tank 5 from the new powder tank 13 by the injector 14, and the supply line of the new powder 12 is provided above the paint tank. In addition, a cyclone 8 is installed in order to separate the powder paint and the carrier air.

  The cyclone 8 flows the powder paint into the funnel-shaped or cylindrical cyclone body together with the carrier air so as to draw a vortex, and exhausts the carrier air from the center of the circle of the cyclone body to discharge the powder paint. This is a device that centrifuges and separates the separated powder coating material against the wall surface of the cyclone body, and then collects the powder coating material under the cyclone body by gravity. In the present invention, the exhaust above the cyclone 8 is forcibly exhausted by the exhaust injector 9 installed at the lower side of the painting booth 1.

  Since dust and the like are mixed in the overspray powder, the cyclone 8 in the overspray powder collection line and the paint tank 5 are connected via the vibrating sieve 10. Further, the lower outlet of the cyclone 8 and the upper inlet of the vibrating screen 10 are directly connected via a flexible tube 11.

  The lower part of the cyclone 8 installed in the supply line of the new powder 12 is directly connected to the paint tank 5 through the flexible tube 11.

  The flexible tube 11 may be made of any material that can be shrunk and shrunk by the suction force from the inside, and can be restored from the contracted state by releasing the suction force. For example, in addition to the American rubber tube, nylon, silicon rubber, campus Canvas, soft resin, etc. can be used.

  In the embodiment of FIG. 1, a candy rubber tube having a diameter of 100 mm, a length of 300 mm, and a thickness of 1.2 mm is used as the flexible tube 11.

  In the embodiment of FIG. 1, an exhaust injector 9 installed at the lower part of the painting booth 1 is used as a forced exhaust device for the cyclone 8, and the exhaust injector 9 is driven and controlled as follows.

  First, the transport injector 6 is operated, and the overspray powder collected by the dust collector 3 is supplied to the cyclone 8 by the transport air. At the same time, the exhaust injector 9 is operated to perform forced exhaust from above the cyclone 8.

  Then, as shown in FIG. 2 (b), the flexible tube 11 below the cyclone 8 is shrunk and contracted by the suction air by forced exhaust from above the cyclone 8, and no air enters from below the cyclone 8. The powder coating is deposited on the closed flexible tube 11 under the cyclone 8 in the locked state.

  The air balance when contracting the flexible tube 11 below the cyclone 8 is such that the exhaust air amount of the exhaust injector 9 from the upper part of the cyclone 8 is larger than the transport air amount supplied to the cyclone 8 by the transport injector 6. Don't be.

  As described above, according to the present invention, the flexible tube 11 naturally contracts due to forced exhaust from above the cyclone 8, so that it is difficult to apply a strong pressure (squeezing) to the collected powder adhered in the flexible tube 11. Therefore, the recovered powder is less likely to harden and the occurrence of powder coating flaws is reduced.

  Next, when the drive of the exhaust injector 9 is turned off, forced exhaust from above the cyclone 8 is eliminated, so that the flexible tube 11 is opened by the elasticity of the flexible tube 11 as shown in FIG. The powder paint collected on the flexible tube 11 below the cyclone 8 falls on the vibrating screen 10 below. In the conveying line for the new powder 12, the powder paint collected at the lower part of the cyclone 8 falls directly into the paint tank 5.

  When the drive of the exhaust injector 9 is turned on again, the flexible tube 11 below the cyclone 8 is naturally contracted by forced exhaust from the center of the cyclone 8 upward as shown in FIG. The lower part of the cyclone 8 is air-locked.

  In the above embodiment, the transport injector 6 and the exhaust injector 9 are simultaneously turned ON and OFF. The ON time was set to 10 seconds and the OFF time was set to 20 seconds. When the transport injector 6 and the exhaust injector 9 are turned OFF, the powder coating material accumulated on the contracted flexible tube 11 naturally falls onto the vibrating sieve device 10 installed therebelow. In this way, by the ON / OFF of the transport injector 6 and the exhaust injector 9, the powder paint can be discharged quantitatively per unit time.

  When the flexible tube 11 is formed of cloth or campus, the flexible tube 11 may be difficult to open even if the suction by forced exhaust air at the top of the cyclone 8 is released. However, even in such a case, since the powder paint is opened by the weight of the powder paint accumulated in the flexible tube 11 and opened by the vibration of the vibrating screen 10, the powder paint falls naturally.

  The vibration sieve machine 10 is adapted to disperse and finely select the powder coating material while gradually rotating from the center of the sieve mesh. When the powder coating material containing air flows into the wire mesh on the vibration sieve 10, the powder coating slides on the mesh screen and flows into a dust chute installed on the corner side of the mesh screen. The time setting is set based on the selection capability of the vibration sieve 10 such as the mesh of the vibration sieve 10 and the particle size of the powder coating material.

  In the above example, the transport injector 6 and the exhaust injector 9 are turned on and off at the same time. However, for example, the exhaust injector 9 may be turned on faster or turned off later. The air balance when contracting the flexible tube 11 below the cyclone 8 is such that the exhaust air amount of the exhaust injector 9 from the upper part of the cyclone 8 is larger than the transport air amount supplied to the cyclone 8 by the transport injector 6. You can do it.

  Next, FIG. 3 shows another embodiment of the present invention. In the embodiment of FIG. 1, the new powder 12 is supplied to the paint tank 5, and the new powder 12 and the recovered powder are mixed in the paint tank 5, but in the embodiment of FIG. The new powder 12 is supplied from the new powder tank 13 toward the cyclone 8, and the new powder 12 and the collected powder are mixed in the cyclone 8.

It is the schematic which shows the collection | recovery flow of the overspray powder which uses the collection | recovery apparatus of the powder coating material which concerns on this invention. (A) is the fragmentary sectional view which shows the state where the flexible tube 11 installed under the cyclone 8 was opened, (b) is the fragmentary sectional view which shows the state where the flexible tube 11 installed under the cyclone 8 was closed. It is the schematic which shows the other example of the collection | recovery flow of the overspray powder which uses the collection | recovery apparatus of the powder coating material which concerns on this invention. It is the schematic which shows an example of the collection | recovery flow of the overspray powder of a prior art example. It is sectional drawing of the rotor valve installed in the downward direction of the cyclone of a prior art example. (A) is a fragmentary sectional view which shows the state which the pinch valve installed below the cyclone opened, (b) is a fragmentary sectional view which shows the state which the pinch valve installed below the cyclone closed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating booth 2 Cartridge filter 3 Dust collector 4 Coating gun 5 Paint tank 6 Transfer injector 7 Transfer hose 8 Cyclone 9 Exhaust injector 10 Vibrating sieve 11 Flexible tube 12 New powder 13 New powder tank 14 Injector

Claims (2)

A cyclone that separates the carrier air and the powder paint is installed at the top of the paint tank. The powder paint is conveyed to the cyclone by the carrier air, and the carrier air is discharged upward from the center of the cyclone circle. In the powder coating material recovery device in the powder coating device that drops the paint below the cyclone and separates it from the carrier air, and stores the separated powder paint in the paint tank installed below the cyclone, together with the carrier air in the cyclone A transport injector that supplies powder paint is installed , a flexible tube with flexibility is connected to the outlet below the cyclone, a forced exhaust device is connected to the top of the cyclone, and the above-mentioned transport injector is operated to powder the cyclone. When the body paint is supplied by carrier air, the forced exhaust device is driven. A deflection Shiki state Bull tube closed by contraction of the cyclone downward, by stopping the forced ventilation system, the powder paint recovery device of the powder coating apparatus characterized in that to open the cyclone under the deflection Shiki Bull tube.   The powder coating material recovery apparatus in the powder coating apparatus according to claim 1, wherein a vibrating screen is installed between the flexible tube below the cyclone and the coating material tank.

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